Added use of pytest-forked to CI unit test runs

Due to apparent bugs in pyparsing, this can significantly speed up unit test execution.

Also:
- Removed use of pexpect in unit tests

Author: tleonhardt

CHANGELOG.md

@@ -1,4 +1,4 @@
-## 0.8.1 (TBD, 2018)
+## 0.8.1 (March TBD, 2018)
 
 * Bug Fixes
     * Fixed a bug if a non-existent **do_*** method was added to the ``exclude_from_help`` list
@@ -16,7 +16,7 @@
     * ``exclude_from_help`` and ``excludeFromHistory`` are now instance instead of class attributes
     * Added flag and index based tab completion helper functions
         * See [tab_completion.py](https://github.com/python-cmd2/cmd2/blob/master/examples/tab_completion.py)
-* Attributes Removed
+* Attributes Removed (**can cause breaking changes**)
     * ``abbrev`` - Removed support for abbreviated commands
         * Good tab completion makes this unnecessary
 

CONTRIBUTING.md

@@ -65,6 +65,7 @@ The tables below list all prerequisites along with the minimum required version
 ### Optional prerequisites for enhanced unit test features
 | Prerequisite                                | Minimum Version |
 | ------------------------------------------- | --------------- |
+| [pytest-forked](https://pypi.python.org/pypi/pytest-forked)| `0.2` |
 | [pytest-xdist](https://pypi.python.org/pypi/pytest-xdist)| `1.15` |
 | [pytest-cov](https://pypi.python.org/pypi/pytest-cov) | `1.8` |
 
@@ -201,7 +202,7 @@ pip install -U pytest mock
 pip install -U sphinx sphinx-rtd-theme
 
 # Install optional prerequisites for running unit tests in parallel and doing code coverage analysis
-pip install -U pytest-xdist pytest-cov
+pip install -U pytest-xdist pytest-cov pytest-forked
 ```
 
 For doing cmd2 development, you actually do NOT want to have cmd2 installed as a Python package.  
@@ -269,6 +270,13 @@ py.test -n4
 ```
 where `4` should be replaced by the number of parallel threads you wish to run for testing.
 
+If you have the `pytest-forked` pytest plugin for running tests in isolated formed processes, you
+can speed things up even further:
+
+```shell
+py.test -nauto --forked
+```
+
 #### Measuring code coverage
 
 Code coverage can be measured as follows:
@@ -390,11 +398,11 @@ how to do it.
 
 6.  Indicate what local testing you have done (e.g. what OS and version(s) of Python did you run the
     unit test suite with)
-    
+
 7.  Creating the PR causes our continuous integration (CI) systems to automatically run all of the
     unit tests on all supported OSes and all supported versions of Python.  You should watch your PR
     to make sure that all unit tests pass on Both TravisCI (Linux) and AppVeyor (Windows).  
-    
+
 8.  If any unit tests fail, you should look at the details and fix the failures.  You can then push
     the fix to the same branch in your fork and the PR will automatically get updated and the CI system
     will automatically run all of the unit tests again.

setup.py

@@ -77,7 +77,7 @@
     INSTALL_REQUIRES += ['subprocess32']
 
 # unittest.mock was added in Python 3.3.  mock is a backport of unittest.mock to all versions of Python
-TESTS_REQUIRE = ['mock', 'pytest', 'pexpect']
+TESTS_REQUIRE = ['mock', 'pytest', 'pytest-xdist', 'pytest-forked']
 DOCS_REQUIRE = ['sphinx', 'sphinx_rtd_theme', 'pyparsing', 'pyperclip', 'six']
 
 setup(

tests/test_cmd2.py

@@ -11,7 +11,6 @@
 import tempfile
 
 import mock
-import pexpect
 import pytest
 import six
 
@@ -1502,37 +1501,3 @@ def test_poutput_none(base_app):
     out = base_app.stdout.buffer
     expected = ''
     assert out == expected
-
-
-@pytest.mark.skipif(sys.platform == 'win32' or sys.platform.startswith('lin'),
-                    reason="pexpect doesn't have a spawn() function on Windows and readline doesn't work on TravisCI")
-def test_persistent_history(request):
-    """Will run on macOS to verify expected persistent history behavior."""
-    test_dir = os.path.dirname(request.module.__file__)
-    persistent_app = os.path.join(test_dir, '..', 'examples', 'persistent_history.py')
-
-    python = 'python3'
-    if six.PY2:
-        python = 'python2'
-
-    command = '{} {}'.format(python, persistent_app)
-
-    # Start an instance of the persistent history example and send it a few commands
-    child = pexpect.spawn(command)
-    prompt = 'ph> '
-    child.expect(prompt)
-    child.sendline('help')
-    child.expect(prompt)
-    child.sendline('help history')
-    child.expect(prompt)
-    child.sendline('quit')
-    child.close()
-
-    # Start a 2nd instance of the persistent history example and send it an up arrow to verify persistent history
-    up_arrow = '\x1b[A'
-    child2 = pexpect.spawn(command)
-    child2.expect(prompt)
-    child2.send(up_arrow)
-    child2.expect('quit')
-    assert child2.after == b'quit'
-    child2.close()

tox.ini

@@ -13,104 +13,104 @@ setenv =
 deps =
   codecov
   mock
-  pexpect
   pyparsing
   pyperclip
   pytest
   pytest-cov
+  pytest-forked
   pytest-xdist
   six
   subprocess32
 commands =
-  py.test {posargs: -n 2} --cov=cmd2 --cov-report=term-missing
+  py.test {posargs: -n 2} --cov=cmd2 --cov-report=term-missing --forked
   codecov
 
 [testenv:py27-win]
 deps =
   codecov
   mock
-  pexpect
   pyparsing
   pyperclip
   pyreadline
   pytest
   pytest-cov
+  pytest-forked
   pytest-xdist
   six
   subprocess32
 commands =
-  py.test {posargs: -n 2} --cov=cmd2 --cov-report=term-missing
+  py.test {posargs: -n 2} --cov=cmd2 --cov-report=term-missing --forked
   codecov
 
 [testenv:py34]
 deps =
   mock
-  pexpect
   pyparsing
   pyperclip
   pytest
+  pytest-forked
   pytest-xdist
   six
-commands = py.test -v -n2
+commands = py.test -v -n2 --forked
 
 [testenv:py35]
 deps =
   mock
-  pexpect
   pyparsing
   pyperclip
   pytest
+  pytest-forked
   pytest-xdist
   six
-commands = py.test -v -n2
+commands = py.test -v -n2 --forked
 
 [testenv:py35-win]
 deps =
   mock
-  pexpect
   pyparsing
   pyperclip
   pyreadline
   pytest
+  pytest-forked
   pytest-xdist
   six
-commands = py.test -v -n2
+commands = py.test -v -n2 --forked
 
 [testenv:py36]
 deps =
   codecov
   mock
-  pexpect
   pyparsing
   pyperclip
   pytest
   pytest-cov
+  pytest-forked
   pytest-xdist
   six
 commands =
-  py.test {posargs: -n 2} --cov=cmd2 --cov-report=term-missing
+  py.test {posargs: -n 2} --cov=cmd2 --cov-report=term-missing --forked
   codecov
 
 [testenv:py36-win]
 deps =
   mock
-  pexpect
   pyparsing
   pyperclip
   pyreadline
   pytest
+  pytest-forked
   pytest-xdist
   six
-commands = py.test -v -n2
+commands = py.test -v -n2 --forked
 
 [testenv:py37]
 deps =
   mock
-  pexpect
   pyparsing
   pyperclip
   pytest
+  pytest-forked
   pytest-xdist
   six
-commands = py.test -v -n2
+commands = py.test -v -n2 --forked